Determination of Multiple Elements in Aquatic Products Using a Graphite Furnace Atomic Absorption Spectroscopy

Significance of the Topic

The accurate determination of trace heavy metals in aquatic products is critical for food safety, environmental monitoring, and regulatory compliance. Seafood matrices present complex, high-salt backgrounds that can lead to significant interferences during graphite furnace atomic absorption spectroscopy (GFAAS) analysis. Optimized background correction and sample preparation are essential to ensure reliable results.

Objectives and Study Overview

This study evaluated the measurement of lead (Pb), cadmium (Cd), copper (Cu), cobalt (Co), and nickel (Ni) in two certified reference materials—TORT-2 lobster pancreas and CRM 278R mussel tissue—using an Agilent 240Z GFAAS system. The goals were to assess method accuracy, precision, and the effectiveness of matrix modifiers for interference removal.

Methodology and Instrumentation

Sample Preparation:

• Freeze samples, then dry and homogenize.
• Digest 10 mg dried sample in 100 µL HNO₃ at 80 °C for 3 hours in closed vessels.
• Cool and dilute to 2 mL with ultrapure water (≈ 3% HNO₃ final).

Instrumentation:

• Agilent 240Z GFAAS with longitudinally heated CTZ graphite furnace.
• Transverse AC-modulated Zeeman background correction.
• PSD 120 autosampler for automatic standard preparation, sample dilution, and modifier addition.
• Optimized parameters: element-specific wavelengths, lamp currents, slit widths, sample volumes, and two chemical modifiers (Pd(NO₃)₂ and Mg(NO₃)₂).

Main Results and Discussion

Calibration curves for Pb, Cd, and Ni exhibited excellent linearity when prepared by the PSD 120. Replicate analyses (n≈45–56) yielded recoveries within ±10% of certified values for all elements in both reference materials. Transverse Zeeman background correction effectively removed large variable backgrounds, revealing clear analyte peaks and demonstrating the high sensitivity of the CTZ furnace.

Benefits and Practical Applications

• Minimal sample mass required reduces matrix handling and reagent consumption.
• Automated standard and sample preparation improves throughput and reproducibility.
• Robust background correction ensures reliable quantification in complex saline matrices.
• Applicable to routine food safety testing, environmental monitoring, and QA/QC in laboratories with limited sample quantities.

Future Trends and Potential Applications

Advances may include coupling GFAAS with hyphenated techniques, expanding multi-element analysis, further miniaturization of sample digestion, and integration with high-throughput automation. Emerging backgrounds correction algorithms and novel modifiers could broaden applicability to diverse biological and environmental matrices.

Conclusion

The presented method demonstrates accurate, precise determination of trace heavy metals in seafood with minimal sample input and full automation of preparative steps. The combination of CTZ furnace geometry and transverse Zeeman background correction delivers reliable results in complex matrices.

Used Instrumentation

Agilent 240Z graphite furnace atomic absorption spectrometer with Transverse Zeeman background correction and PSD 120 autosampler.

References

No additional references were provided in the original application brief.